developing a methodology for mapping local soil types along the buganda...

Feed the Future Innovation Lab for Collaborative

Research on Grain Legumes

Developing a methodology for mapping local soil types along the Buganda Catena, Uganda

Tenywa, M.M. O Semalulu, R Miiro, S S. Kyebogola, P. Kyomuhendo, CL Kizza,

JGM Majaliwa, J. Nampijja, AW. Lenssen, B. Miller, L. Burras and R.

Mazur

Feed the Future Innovation Lab for Collaborative Research on Grain Legumes

IntroductionFarmer’s knowledge on soil and landmanagement strategies is valuable for developingimproved technologies for sustainable soilfertility management for a specific purpose (e.g.increasing bean productivity);The correlation and communication betweenindigenous soil classification system (ISCS) andconventional classification (FAO-UNESCO-ISRIC,1990, US-Taxonomy) must be understood;This requires mapping the local soil types in a GIS.


Problem Statement Limited understanding of the Indigenous soil classification

system (ISCS) Inefficiency of extension workers in service delivery Communication barrier between extension workers and

farmers; Soils seeming to be complex and highly heterogeneous to

extension workers; Criteria used by farmers to classify soils into different

categories not documented; Underutilization of existing knowledge on soils (e.g. Catena

concept, FAO-UNESCO, US-Taxonomy); Transferability of science and technology (soil test kit,

fertilizers) limited; Inability to identify vulnerable soils that require specialized

management.


Catena Soil class Catena soils type Local name Transiliteration

FAO (1975)

Bugandacatena(Associated withExtensiveRemnantsof theBugandaSurface)

Summit- hillbrown soils

Ferruginised Luyinjayinja Stony AcricFerralsol

Red earth Buganda loam (hasstoniline)

Limyufumyufu

Reddish GleyicArenosol

Buganda clay loam(middle, sloppingpediment

Lidugavu Black AcricFerralsol

Buganda "brownferruginised"sandy loam

Limyufumyufu-stoney

Reddishstony

GleyicArenosol/AcricFerralsol

Swampfringes

Arenic Lusenyusenyu

Sandy GleyicArenosol

Swamp soils Gleysol Lubumbabumba/ toosi

Clayey


Surface Soilclass

Catenasoils type

Local name pH %OM

BS Order Group FAO (1975)

Bugandasurface

Summit- hillbrownsoils

Ferruginised

Luyinjayinja Slightly acid

3.5-4 50-60

Ferralsol

Pisoplinthic Acric Ferralsol

Redearth

Bugandaloam (hasstoniline)

Limyufumyufu

Medium acid

2-2.5 60-75 Cambisol Sideralic Gleyic Arenosol

Bugandaclay loam(middle,sloppingpediment

Lidugavu Medium acid

2.5-3 50-75 Phaeozem Cambic Acric Ferralsol

Buganda"brownferruginised" sandyloam

Limyufumyufu-stoney

Strongly acid

2-2.5 30-40 Ferralsol Pisoplinthic/Ferritic

Gleyic

Arenosol/ Acric

Ferralsol

Swampfringes

Arenic Lusenyusenyu

Arenosol Gleyic Gleyic Arenosol

Swampsoils

Gleysol Lubumbabumba/ toosi

Phaeozem Gleyic/Stagnic/Fluvic

Sand Lusenyusenyu

Extremelyacid

4-7 2-5 Arenosol Gleyic/Fluvic/Eutic/Sideralic


FAO and Buganda Catena series Generalization of local soil types


Broad and specific objectivesTo gain improved understanding of the ISCS and

increase its utility;1. To assess the conventional and topo-sheet guided

method for mapping local soil types into a GIS; 2. To determine the categorical levels of ISCS for soils

along the Buganda catena.Hypotheses

1. Local soils maps developed using different methods can all be captured into a GIS;

2. ISCS is not hierarchical i.e not amenable to classification at different categorical levels.


Approach and methodologyLocation of the study areaThe district is located 1100 m above sea level. The study was conducted in two sub-counties, namely; Kabonera and Mukungweof Masaka district located in central Uganda at 31.7361oE latitude and 0.34111oS longitude. Soils : Masaka district is dominated with by Acric Ferralsols (75%)

and Gleyic Arenosol (25%) (FAO, 1975) or Ferralsols (70%), Nitisols(5%), and Glysols (25%) (NARO, 2001; NEMA, 2009).ClimateMasaka district climate is categorized as tropical wet and dry or savanna and typically experiences two rainy seasons with peaks in March to June (Season A) and August to November (Season B). Average annual rainfall is 1350 mm & the average monthly temperature varies from 19 to 27oC.Farming system: Banana-Coffee


Mapping local soil typesSteps Conventional Topo-sheet based1 Selection of key informants to

participate in FGDsOutput: List of key informants

Identification of key informants to participate in FGDsOutput: List of key informants

2 FGDs to explore farmer’s knowledge of local soil types Output: Soil types

FGDs to explore farmer’s knowledge of local soil types Output: Soil types

3 Sketching local soil types on a mapOutput: Village soil map

Participatory sketching of local soil types Output: Village soil map

4 Transect walk and georeferencingsome pointsOutput: georeferenced village soil map

Participatory mapping of local soil onto area topo-sheet (1:50,000) & transfer on enlarged (1:5,000) topo-sheetsOutput: Village soil map on scale

5 GIS-analysis of georeferencedvillage soil mapOutput: Failed overlay as for lack of scale.

GIS-analysis of village soil map on scaleOutput: GIS overlay of local soil types.


Overlaying local soil map on enlarged top-sheets 1:5,000


Hierarchicalization of ISCS

The farmers and extension workers were separately engaged in an iterative Q&A process to explore their understanding of local soil types in terms of criteria for classification, occurrence on the land scape position, indicator plants, productivity, colour, texture)

Guiding questions to exploring the ISCS- hierarchicalization• What are the local indicators for the different soil types?• How can soil types named based on colour be further

distinguished (hierarchicalization)?• How can soil types based on texture be further distinguished?• What are the different categories/criteria that underpin the ISCS?• What indicators are used to distinguish sub-categories at

different levels of hierarchicalization?


ResultsMapping local soil types Rejected the null hypothesis that conventional and

improved local soil maps can be captured in a GIS; Accepted the alternative that local soil map overlain

on enlarged top-sheets (1:5,000) can be captured in a GIS.

Hierachicalization of ISCS Rejected the null hypothesis that ISCS NOT hierachical Confirmed that a local soil type has sub-types/sub-

grades based on specific criteria on which the improvements in the hierarchies can be made.


Mapping of local soil types


Soil typeColour

Texture

Consistency

Productivity

DepthCrops

*Indicator plants

Position on

landscape

Rema

Liddugavu elitalimumayinja (Black without stones)

Black LoamSticky, dries quickly 1 Deep

Bananas, Beans, Coffee

Wandering Jew, Kafumbe, Ebituntugulu, Enseke

Lower slopes

Friable condition (Kiwugankofu) possible

Liddugavu elyamayinja (Black with stones)

Black Stony

Soggy-wet, drains quickly, sticks on hoe

2 Less deep

G.nuts, Potatoes, Beans, Maize, Irish potato

Shrubs, obusana, Embubu

Summit

Limyufumyufu elitalimumayinja (Reddish without stones)

Reddish Loam

Easy to work, Drains well, sticks on hoe

4 Shallow (2-3ft)

Coffee, Cassava, Bogoya-Musa

Panicum maximum

Backslope (middle)

Lunyu condition possible

Limyufumyufu lyamayinja (Reddish with stones)

Reddish Stony Sandy, Scratchy,

5 Shallower

Agro-trees;Coffee, mango, avocadoes, oranges

Ekisula Footslope

[Lubumbabumba (Clayey)

Grey Clayey

Very sticky 3 DeepBeans, Maize, Sugarcane, Yams, Ntula

Papyrus Toe-slope

Lusenyusenyu (Sandy) Sandy Loose 6 V.poor DeepPotato, Sugarcane-hardy, Oranges

Ebisalu, Egugu, Mpoja

Toe-slope

* Need for botanical identification, Luyinjayinja (gravelly) got lost in the hierachicalization of the original major soil types

Table showing attributes of the local soil types in Kabonera sub county, Bisanjeparish at Kagganda Village


Criteria used for sub-division in ISCS according to Extension workers

Class Subclasses Criteria

Liddugavu Kiwugankofu Texture (Liyiika)

Liddugavu *Eryekibira (under forest) LocationLidugavu limpi DepthLidugavu panvu Depth*Eryolwazi (overlying the rock) Depth

Limyufu Eryolufufu Texture*Olukusikusi (clayer) ColourElyoluyinja Texture

Lubumbabumba Lubumbabumba Elyolusenyusenyu TextureLubumbabumba Oludugavu Colour

Olusenyusenyu Olusenyusenyu Lwolubumbabumba TextureOlusenyusenyu oludugavu ColourOlusenyusenyu Lwamayinja amanene Particle sizeOlusenyusenyu Lwamayinja amatono Particle size


Four (4) Categories levels for hierachicalization of soils by farmers in Kaganda village

Landscape Upper Lower Upper Lower Lower Lower Lower

Colour LidugavuLidugavu

Limyufumyufu

Limyufumyufu

Texture

Lidugavuelyamayinja

Lidugavutelilinamayinja

Limyufumyufu elyamayinja

Limyufumyufu telilina mayinja

Lubumbabumba

Lubumbabumba

Lusenyusenyu

Fertility

Fertile black Lubumbabumba clayey (tossi nyo)-Entobazi

Less fertile grey Lubumbabumba (Bisalu)

Infertile Lusenyusenyu

Criteria used for categorization of soils by farmers


GIS distribution of local soil types across ISCSFarmer's Classification

Soil types Black Clayey Black Black Stony Red Red StonyRed 0.0% 0.0% 0.0% 72.7% 27.3%Upper Black 0.0% 33.3% 66.7% 0.0% 0.0%Lower Black 0.0% 66.7% 33.3% 0.0% 0.0%Histosol 61.5% 38.5% 0.0% 0.0% 0.0%

Digital Hillslope Position distribution of ISCS based soil typesFarmer's Classification

Position Black Clayey Black Black Stony Red Red StonySummit 0.0% 66.7% 33.3% 0.0% 0.0%Shoulder 0.0% 11.8% 23.5% 41.2% 23.5%Backslope 0.0% 0.0% 0.0% 50.0% 50.0%Footslope 8.3% 25.0% 8.3% 58.3% 0.0%Toeslope 63.6% 36.4% 0.0% 0.0% 0.0%

Distribution of local soil types in Kagganda-Mukungwe S/C on Gondwana Surface


GIS distribution of local soil types across ISCSFarmer's Classification

% Black Clayey Black Friable Black Black Stony Red Red StonyRed 0.0% 0.0% 0.0% 0.0% 72.2% 27.8%Upper Black 0.0% 0.0% 0.0% 100.0% 0.0% 0.0%Lower Black 9.1% 0.0% 81.8% 9.1% 0.0% 0.0%Valley Black 50.0% 25.0% 25.0% 0.0% 0.0% 0.0%Histosol 100.0% 0.0% 0.0% 0.0% 0.0% 0.0%

Digital Hillslope Position distribution of ISCS based soil typesFarmer's Classification

% Black Clayey Black Friable Black Black Stony Red Red StonySummit 0.0% 0.0% 30.0% 10.0% 40.0% 20.0%Shoulder 0.0% 0.0% 33.3% 11.1% 22.2% 33.3%Backslope 0.0% 33.3% 0.0% 0.0% 33.3% 33.3%Footslope 12.5% 0.0% 37.5% 0.0% 50.0% 0.0%Toeslope 50.0% 0.0% 16.7% 0.0% 33.3% 0.0%

Distribution of local soil types in Kiwanyizi-Mukungwe S/C on African/Tanganyika Surface


Soil Resource

Upland

Lidugavu/Black

Lyamayinja/Stony

Telilina mayinja/Without stones

Limyufu/Reddish

Lyamayinja/Stony

Telilina mayinja/

Without stones

Lowland

Lidugavu/Black

Lyamayinja/Stony


Limyufu/Reddish

Lyamayinja/Stony


Hierachicalization of the ISCS; as knowledge increases ISCS changes


ConclusionImprovements in the ISCS holds a promise for:Sustainable soil management-ISFM & SWCEmpowering extension workers for service deliveryFostering collective action in the communitiesSaving costs involved in soil management (e.g.

fertilizers, lime)Saving time used in service deliveryMore relevant training-curriculaIncreased utilization of available knowledge (e.g. FAO-

UNESCO, US-Taxonomy, Buganda Catena)


Wayfoward• Validation of DEM- based ISCS predictions in

new areas• Dissemination of package of improved ISCS

tools (village soil map, block diagram & soil analytical data)

• Capacity development for extension workers to utilize ISCS package;

• Exploring Curriculum improvement to include ISCS


Acknowledgements

• Government of Uganda- Makerere University, NARO

• Feed the Future Legume innovation Lab• Local governments of Masaka and Rakai• Partner organizations• Bean Innovation Platform members

God bless you. Thank you

developing a methodology for mapping local soil types along the buganda...

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